import { db } from '../config/firebase'
import { RevenueCatEvent } from '../types'

const PREMIUM_ACTIVE_TYPES = new Set([
  'INITIAL_PURCHASE',
  'RENEWAL',
  'PRODUCT_CHANGE',
  'TRANSFER',
  'UNCANCELLATION',
])

const PREMIUM_REVOKED_TYPES = new Set([
  'EXPIRATION',
  'CANCELLATION',
  'SUBSCRIBER_ALIAS',
])

const PREMIUM_ENTITLEMENT_ID = 'closer_premium'

export async function syncEntitlement(event: RevenueCatEvent): Promise<void> {
  const { type, app_user_id: uid, id: eventId } = event.event

  // Check idempotency - skip if we've already processed this event
  const eventRef = db().collection('entitlement_events').doc(eventId)
  const eventDoc = await eventRef.get()
  if (eventDoc.exists) {
    console.log(`[entitlement] skipping duplicate event: ${eventId}`)
    return
  }

  // Store event for idempotency (with 7-day TTL via Firestore rule or scheduled cleanup)
  await eventRef.set({ processedAt: new Date() })

  // Verify entitlement_id matches expected premium entitlement
  const entitlementId = event.event.entitlement?.identifier || event.event.entitlement_id
  if (entitlementId !== PREMIUM_ENTITLEMENT_ID) {
    console.log(`[entitlement] ignored event for wrong entitlement: ${entitlementId} (expected: ${PREMIUM_ENTITLEMENT_ID})`)
    return
  }

  if (PREMIUM_ACTIVE_TYPES.has(type)) {
    await db().collection('users').doc(uid).update({ hasPremium: true })
    console.log(`[entitlement] hasPremium=true for ${uid} (${type})`)
    return
  }

  if (PREMIUM_REVOKED_TYPES.has(type)) {
    await db().collection('users').doc(uid).update({ hasPremium: false })
    console.log(`[entitlement] hasPremium=false for ${uid} (${type})`)
    return
  }

  console.log(`[entitlement] ignored event type: ${type}`)
}